For one night only, the Calgary Roughnecks owed the Colorado Mammoth a little thanks.

The Mammoth beat the Arizona Sting 16-11 last night in the Mile High City to clinch a National Lacrosse League playoff berth but the victory also gave Calgary and the Portland Lumberjax a ticket to the post-season.

The Riggers, winners of five of their last six games including a 12-10 victory over the San Jose Stealth Saturday night, make the playoffs for the fourth straight season in the franchise's five-year existence.

Calgary coach Chris Hall admitted it's nice to have a playoff berth locked up but his team is shooting for loftier goals.

"We're certainly happy to have a playoff spot, it's been a great weekend for us," said Hall. "We're in the position where other teams have to chase us now. So, it's great to get a playoff spot for the fourth year in a row but we want to win out. This is only the first step."

Calgary is tied atop the West Division with Colorado and Portland at 8-5. The Riggers have three games left. They face Arizona at the 'Dome next weekend before finishing the season with a home-and-home series against the Mammoth.

Clinching first in the West has been a season-long goal for the Roughnecks. Captain Tracey Kelusky said following the win over San Jose his club wants to play for the home crowd.

"We want to get a home playoff game here for our fans and for our ownership group," said Kelusky.

"If we do what we have to and win out, we'll be peaking at the right time to take another run at another championship."

Calgary won the NLL championship in 2004 and finished first in the West last season before losing to the Sting in the West Division championship at the 'Dome.